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Biomedical subjects

E M Sedgwick

Publications and source records attributed to E M Sedgwick.

At least 55 records · Page 3Linked to original sources
PubMed1983

Spinal cord stimulation in peripheral vascular disease.

The results of ten patients with severe, intractable symptoms of arterial disease receiving spinal cord stimulation are reported. Six out of ten patients showed clinical improvement. Three of five patients with severe rest pain obtained complete or very marked relief and one of two patients with moderate rest pain in the legs obtained complete relief. The mean claudication distance in the ten patients increased from 65 to 212 metres during epidural stimulation of the spinal cord. Exercise tolerance as measured on a bicycle ergometer increased by 61%. These changes were associated with small increases in cutaneous and muscle blood flow. In those patients who responded clinically, the improvements seen were maintained as long as spinal cord stimulation was continued. There was no clinical response to transcutaneous (placebo) stimulation and four patients did not respond in any way to spinal cord stimulation. The improvements seen are unlikely to be due to either the natural history of the disease or to a placebo effect. The effect is probably due to antidromic stimulation of the central processes of the first order sensory neurons. It is suggested on the basis of animal studies that this effect may be mediated by release of prostaglandins as well as indirectly via pain relief.

Adult↗
PubMed1983

The effect of spinal cord stimulation upon peripheral blood flow in patients with chronic neurological disease.

The impact of spinal cord stimulation (SCS) upon patients with chronic neurological disease appears to be primarily upon autonomic functions. There is clinical evidence of increased blood flow in the lower limbs. In the present study, cutaneous blood flow was measured by means of xenon clearance in the legs and feet of patients receiving SCS for chronic neurological disease. In 8 patients pre-SCS cutaneous blood flow was compared with that during SCS. In 7 out of the 8 patients there was an increase in total cutaneous blood flow during stimulation. The mean pre-SCS value was 2.43 +/- 1.57 ml per 100 g of tissue and this rose to 3.23 +/- 1.81 ml per 100 g of tissue per minute during stimulation. The possible mechanisms for the increased cutaneous blood flow are discussed.

Adult↗
PubMed1983

The quantitative assessment of the influence of spinal cord stimulation on motor function in patients with multiple sclerosis.

This paper gives the results of quantitative measurements of motor function made in a group of 23 patients receiving spinal cord stimulation (SCS) for multiple sclerosis. Although 14 out of the 23 patients reported subjective improvement in motor function and many felt these improvements were significant to them, only 4 patients showed an improvement in pyramidal function, only 1 in cerebellar function. There was no statistically significant improvement in walking speed. It is concluded that SCS does not have a major impact upon motor disability in multiple sclerosis and bladder dysfunction remains the main indication for SCS.

Activities of Daily Living↗
PubMed1982

Age-related changes in monosynaptic reflex excitability.

The excitability of the H-reflex was tested in a younger group (19 to 31 years) and an older group (60 to 72 years) of subjects. The threshold for the H-reflex was higher and the reflex latency was 7 msec longer in the older group of subjects. Also, the H-reflex amplitude was significantly smaller, longer in duration and polyphasic in shape whereas the time delay between the M-response and the H-reflex (central latency) was 5 msec longer in the older group. The H-reflex recovery curves of the older subjects demonstrated a longer primary inhibition period (94 msec in older subjects, 44 msec in younger subjects) and was slower, more inhibited, and took a longer time for maximal recovery. In accordance with previous findings, these results are attributed to possible central as well as peripheral and muscle fiber defects in old subjects. Such changes must be taken into account when using H-reflex tests in the clinic.

Aged↗
PubMed1982

Linkage of autosomal dominant type I hereditary motor and sensory neuropathy to the Duffy locus on chromosome 1.

Data from English families confirms the probable linkage of the loci for autosomal dominant type I hereditary motor and sensory neuropathy (HMSN) and the Duffy blood group. The locus for autosomal dominant type I HMSN is in chromosome 1 near the centromere, about 15 centimorgans from the Duffy locus. The linkage between type I HMSN and the Duffy locus and the two recombinants found between Duffy and type II HMSN support the hypothesis that there are at least two genetic variants of autosomal dominant HMSN.

Adult↗
PubMed1980

Spinal cord stimulation in multiple sclerosis: clinical results.

Clinical results of spinal cord stimulation by means of epidural electrodes are reported in 19 patients with multiple sclerosis. On temporary stimulation with percutaneous electrodes, significant improvement in mobility occurred in 27.7% of 18 patients and the same number showed improved sensory function. Only one of 13 patients with severe upper limb ataxia improved. The major response, both in terms of the percentage of patients responding and the extent of the responses seen was in bladder function: 75% of 16 patients with bladder symptoms improved and seven of the 11 patients with severe bladder disturbance (Kurtzke grade 3 or more) improved. Four of these seven patients had before and after cystometry and 3 showed reduced detrusor hyperreflexia. Altogether, 10 patients had a worthwhile clinical response in one or more aspects of the disease and of these, nine have so far gone on to permanent stimulation. Medium-term results (up to two years) show that, with one exception, improvement in bladder function has been maintained as long as stimulation has been continued and at least 50% of improvement in mobility has been maintained. A favourable response depends not upon the fact of stimulation but upon the type of stimulation received. This, along with other evidence, indicates that the response is not caused either by a placebo effect or by the natural fluctuation of the disease.

Adult↗
PubMed1980

Evoked potentials and contingent negative variation during treatment of multiple sclerosis with spinal cord stimulation.

Cervical somatosensory evoked potentials, brainstem evoked potentials, visual evoked potentials, and the cerebral contingent negative variation were recorded in patients with definite multiple sclerosis before, during, and after spinal cord stimulation. Improvements were seen in the cervical somatosensory and brainstem evoked potentials but neither the visual evoked potential nor the contingent negative variation changed in association with spinal cord stimulation. The results indicate that spinal cord stimulation acts at spinal and brainstem levels and that the clinical improvements seen in patients are caused by an action at these levels rather than by any cerebral arousal or motivational effect. The evoked potentials were not useful in predicting which patients were likely to respond to stimulation.

Brain Stem↗
PubMed1980

Spinal cord potentials in traumatic paraplegia and quadriplegia.

Cortical, cervical and lumbar somatosensory evoked potentials were recorded following median and tibial nerve stimulation in patients with traumatic paraplegia and quadriplegia. The isolated cord was able to produce normal potentials even during spinal shock if the vertical extent of the lesion did not involve the generator mechanisms. The cervical potentials showed subtle changes in paraplegia at Th5 levels and below. In high cervical lesions the early cervical potentials may still be present but the later potentials were absent or, in partial lesions, delayed.

Adult↗
PubMed1980

Characteristics of spinal cord-evoked responses in man.

The averaged electrical potentials evoked by the stimulation of the peripheral nerves were recorded with surface electrodes over the lumbosacral, lower thoracic and cervical spine and with epidurally placed electrodes in the cervical area. The waveforms of the lumbosacral and cervical spinal cord potentials show similar complexity reflecting peripheral and central generators. The larger negative wave with at least two components is followed by a slower positive deflection. Evoked potentials recorded over the cervical segments of the spinal cord with epidural electrodes are of much higher amplitude and more complex waveform than those recorded with surface electrodes.

Adult↗
PubMed1980

Electrophysiological responses and stimulus parameters associated with spinal cord stimulation.

Cervical somatosensory-evoked potentials and brainstem-click-evoked potentials were recorded from 10 patients with multiple sclerosis before and after a trial of spinal cord stimulation. An improvement in amplitude of the cervical somatosensory-evoked potential was seen in 7 out of 8 patients, while 3 out of 10 showed a decrease in latency of the brainstem-evoked potential. Stimulus currents were measured during spinal cord stimulation, and those patients requiring high currents to evoke a sensation did not derive clinical benefit from spinal cord stimulation.

Brain Stem↗
PubMed1979

Modulation of the tonic stretch reflex by monoamines.

The effects of L-DOPA and 5-HTP on the tonic stretch reflex (TSR) in the decerebrate rat were studied. L-DOPA facilitated the TSR in a dose-dependent manner. The facilitation of the TSR was blocked by pimozide. A sensitive electromygraphic (EMG) technique capable of recording single motor unit discharges was used. The EMG results suggest that gamma motoneuron sensitivity was increased to a greater degree than alpha motoneuron sensitivity during the facilitation by L-DOPA. The L-DOPA-induced facilitation persisted in animals partly depleted of 5-hydroxytryptamine (5-HT) by reserpine, p-chlorophenylalanine or 5,6-dihydroxytryptamine. 5-HTP inhibited the TSR in a dose-dependent manner. It is concluded that DA not 5-HT is the amine which normally mediates facilitation of the TSR after L-DOPA and that gamma motoneuron activation is more likely to be involved to a greater degree than alpha motoneuron activation in the neural mechanisms of the facilitation.

5-Hydroxytryptophan↗
PubMed1979

Delayed cervical somatosensory potentials in cervical spondylosis.

The cervical somatosensory evoked potential after median nerve stimulation was recorded in 14 patients with cervical spondylosis with radiculopathy and, in 10 cases, myelopathy. Four patients had normal potentials, five showed delayed potentials, and in five others no potential could be seen.

Adult↗
PubMed1979

Chlormethiazole--no hangover effect but not an ideal hypnotic for the young.

The hangover effects of 768 mg chlormethiazole, an hypnotic with a half-life of approximately 4 hr, were compared with those of placebo in a double-blind cross-over study in 8 young subjects. Ten hours after dosing there were no differences between the preparations in the subjects' psychomotor performance, EEG sleep scores, or visual analogue ratings. Thus, an hypnotic which is rapidly removed from the body may confer considerable advantages. However, all 8 subjects had unpleasant nasal symptoms following chlormethiazole, and it is therefore not an ideal hypnotic for this age group.

Adult↗